The antibiotics of the cephalosporin-type play a prominent role in the treatment of human infectious diseases. Thus, e.g. Cephalotine, Cephaloglycine, Cephazoline and Cephalexine (c.f. Belgian patent specification No. 618,663; British patent specification No. 985,747; U.S. Pat. No. 3,516,997; Belgian patent specification No. 696,026, respectively) are widely known, valuable cephalosporin derivatives possessing antibacterial activity.
Presently great efforts are being made in order to prepare novel antibiotics suitable for the treatment of different infectious diseases.
Originally the semisynthetic cephalosporin derivatives were prepared by acylating the 7-amino group of 7-amino-cephalosporanic acid (further referred to as 7-ACA), but the later extensive experiments enabled the preparation of novel derivatives by changing the substituents in the positions 7 and/or 3 of the cephalosporin ring as well (Fortschritte der Chemie Organischer Naturstoff, 28, p. 343-403 (1970)).
A great number of cephalosporin derivatives as well as pharmaceutical compositions have been prepared up to now. Numerous scientific publications, technical books and patents relating to this subject are known (e.g. Flynn, E. H.: "Cephalosporin and Pennicillins", Academic Press, New York and London, 1972; Perlman, D.: "Structure-activity Relationship Among the Semisynthetic Antibiotics", New York, 1977; O'Callaghan, C. H.: Antimicrob. Chemother. 5, 635 (1979)).